This invention relates to a yarn finish. More particularly, this invention relates to a spin finish for polyamide feeder yarn to be processed into plied, bulked, continuous filament carpet yarn by texturing and cabling operations.
Various finishes for synthetic filaments are known. However, none of the prior art teaches the required combination of ingredients to achieve the specific beneficial results of the composition of this invention. The critical ingredients and amounts thereof are shown in the discussion below.
Many of the known finishes flash off of the yarn in high temperature processing, particularly in steam jet texturing. Others cause excessive tension build-up during cabling operations. Still others fail to have emulsion stability or provide insufficient yarn lubrication. Representative prior art patents include
U.s. pat. No. 2,565,403 to Sproule et al., PA1 U.s. pat. No. 3,198,732 to Olney, PA1 U.s. pat. No. 3,306,850 to Olsen, PA1 U.s. pat. No. 3,672,977 to Dardoufas, and PA1 U.s. pat. No. 3,687,721 to Dardoufas.
It has been suggested that coconut oil mixed with a suitable sulfonated natural petroleum product and other essential ingredients may be emulsified with water so as to minimize the quantity of lubricant required and provide an unusually even distribution of finish on the yarn. For example, our recent U.S. Pat. No. 3,781,202 discloses a spin finish for polyamide yarn to be processed at high temperature, said finish being an oil in water emulsion of about 10 to 20 percent by weight of said oil portion, said oil portion consisting essentially of coconut oil, polyoxyethylene castor oil, decaglycerol tetraoleate, glycerol monooleate, polyoxyethylene sorbitan monooleate, polyoxyethylene tallow glyceride, and sulfonated petroleum product.
In the production of bulked, continuous filament carpet yarn from a feeder yarn bearing the spin finish disclosed in U.S. Pat. No. 3,781,202, difficulty has often been experienced in that yarn bearing this finish is not very suitable for high-speed cabling operations to form twist plied yarn because of excessive tension build-up during cabling. The term "cabling" is conventionally used in this art to mean the production of twist plied yarn, and a suitable method and apparatus for twist plied yarn is described in U.S. Pat. No. 3,820,316 to Clarkson. Cabling operations are normally used in fabrication of tufting yarn, which may be utilized in the manufacture of shag carpeting and the like. Typically, a first single end of yarn having no more than a producers twist is plied with a second single end of yarn while both are under tension and advancing at a common linear speed. Since tension on the yarn is maintained by high friction, it is critical that the spin finish on the yarn not interfere with maintaining a relatively constant friction during running.